1. Field of the Invention
The present invention relates to a centrifugal pump having an output which is separated completely sealingly from the driver side by an isolation shell, and which further includes an impeller supported in an overhung position of a shaft between two axial limit stops, the impeller being driven by a magneto coupling acting through the wall of the isolation shell and being subjected in operation to axial thrust forces generated by relatively differing pressures acting on the front and rear sides thereof, the pump having means operative to balance these thrust forces.
Such centrifugal pumps are generally known. They have an extremely wide field of application, especially in the field of chemistry where specifically poisoness and/or other agressive fluids are conveyed.
2. Description of the Prior Art
The inherent difficulty of known centrifugal pumps of the so-called isolation shell motor-pumps or magneto coupling pumps design has been the absorption and balancing of the hydraulic forces within such pumps, specifically of the thrust forces acting onto the impeller. The presently known solutions have not been satisfactory due to their necessitating intrinsic designs which in addition gave rise to relatively high losses of energy (losses due to friction, decrease of efficiency). This is a quite regrettable fact because modern materials allow a more compact design of the drive system proper and thus enable the overall dimensions to be kept to a minimum.